Santiago, The Old Man and the Sea, Ernest Hemingway

SIR ROBIN Knox-Johnston, the spryest of 67-year-olds, has more in common with a young Manolin than a melancholic, unfortunate Santiago, but like many who have travelled the oceans all their lives, something keeps drawing him back.

Knox-Johnston is about to do something extraordinary. On October 22, he will set sail from Bilbao in the oldest single-handed round-the-world race, the renamed Velux 5 Oceans. It is not a non-stop circumnavigation, like the one in which he charted new waters and made his name in 1969, but instead covers three gruelling legs to Fremantle, Australia, on to Norfolk, United States, and back to Bilbao. The breaks will make the racing fiercer as Knox-Johnston, the oldest competitor in the event, takes on men who might be his grandsons. He has not raced at this level since he entered the Atlantic Challenge in 1997, which he did not finish.

But sitting under the hull of one of his old Clipper yachts in the boatyard at Endeavour Quay, Gosport, Knox- Johnston is as relaxed as ever. The naming ceremony is on Friday and he has to be in Bilbao on October 1.

Having been fortunate enough to be on the foredeck for an unorthodox spinnaker change during a storm in the South China Sea, while Knox-Johnston helmed unperturbed, I can say that he is not easily shaken.

He says that he is striking a blow for Grey Power, which is what he called his boat. It is now called Saga Insurance, which amounts to the same thing. It is the same boat, Fila, that won this race in 1998.

“Just because you reach retirement age doesn’t mean your brain turns to porridge, you have a heart attack every time you climb the stairs and you’ve forgotten everything you ever knew,” he said. “Everyone says it’s much harder now, so I thought I’d find out.

“The other reason is I am the only Brit who has ever won a solo round-the-world yacht race, and one of these guys might take that. I don’t know how I’m going to compete, but I’m still pretty wiry and I’m not out there just to be in the race.”

Saga Insurance is a world apart from Suhaili, the boat on which Knox-Johnston set the record for the first single-handed non-stop circumnavigation of the globe. It is the same weight at nine tonnes but almost twice the length of his old faithful sloop, which had a clearance of only 1ft 10in from water to deck. It has four times the sail area, which will give him the speed to ride with weather systems and take, he hopes, 200 days fewer than the 312 days it took him originally.

“People who don’t know me say: ‘You’re mad, you’re too old,’ ” he said. “What a ridiculous thing to say. It’s like before I went round the world the first time, this chap came up to me and said, ‘are you this Johnny who is going to sail singlehanded non-stop round the world? Can’t be done, in any case you couldn’t do it.’ ”

Knox landings

1939: Born March 17, London. Eldest of four brothers

1969: Becomes first to circumnavigate the globe non-stop single-handed after 312 days in Suhaili

1970 and 1974: Wins two-handed Round Britain Race

1977: Skippers Condor in Whitbread Round the World Race. Wins two legs

1994: As co-skipper with Peter Blake of catamaran Enza, wins the Jules Verne Trophy